Adhesive as well as preparation method and application thereof

Abstract

The invention discloses an adhesive, a preparation method and application thereof, and an adhesive composition, which are characterized by comprising the following components based on the total weight: 20-50wt% of silylated polymer (A); 25 to 50 wt% of a filler (B); and 0.05-10 wt% of an antioxidant (C) represented by the following formula I, a sample prepared from the cross-linking adhesive disclosed by the invention has good mechanical properties, and still has excellent mechanical properties even if the sample is soaked in boiling water or under the conditions of high temperature, high humidity or low temperature. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of adhesives for aerospace, and particularly relates to an adhesive, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous development of aerospace technology, the performance requirements for materials are increasing day by day. In the structure of aerospace vehicles, adhesives play a crucial role, and they need to have high strength, good temperature resistance, pressure resistance, and reliable bonding performance, etc. Traditional adhesives may not meet the increasingly stringent requirements in the aerospace field in terms of certain properties. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides an adhesive composition, which, based on its total weight, comprises:

[0004] 20 - 50 wt% of a silylated polymer (A), preferably 28 - 35 wt%;

[0005] 25 - 50 wt% of a filler (B), preferably 27 - 32 wt%; and

[0006] 0.05 - 10 wt% of an antioxidant (C) represented by the following formula I, preferably 0.05 - 5 wt%, and more preferably 0.05 - 2 wt%;

[0007]

[0008] In formula I, R1 is selected from a straight-chain or branched-chain alkyl group of C 12～20 ;

[0009] R2 is an aryl group, such as a phenyl group or a naphthyl group.

[0010] According to an embodiment of the present invention, the silylated polymer (A) is selected from at least one of the compounds represented by the following formula II, formula III, or formula IV:

[0011]

[0012] wherein, R 3 are the same or different and are independently selected from C 1-6 alkylene;

[0013] R 4 , R 5 are the same or different and are independently selected from C 1-4 alkyl;

[0014] X represents a divalent group selected from -NH- or -S-;

[0015] f is an integer from 1 to 6, preferably from 2 to 5, more preferably from 2 to 4, even more preferably from 2 to 3;

[0016] R 1 is selected from C 1-6 alkylene.

[0017] Preferably, in formula (II), (III) and / or (IV), P represents a polymer group selected in a non-limiting manner from polyethers, polycarbonates, polyesters, polyolefins, polyacrylates, polyether polyurethanes, polyester polyurethanes, polyolefin polyurethanes, polyacrylate polyurethanes, polycarbonate polyurethanes and block polyether / polyester polyurethanes.

[0018] For example, EP2468783 describes a silylated polymer of formula (II), wherein P represents a polymer group containing polyurethane / polyester / polyether blocks. The polymer of formula (II) can be obtained according to the methods described in documents EP2336208 and WO2009 / 106699.

[0019] The polymer of formula (III) can be obtained by hydrosilylation of polyether diallyl ether according to the method described in document EP1829928, for example.

[0020] The polymer of formula (IV) can be obtained, for example, by reacting a polyol with one or more diisocyanates, followed by reaction with an aminosilane or a mercaptosilane. The method for preparing the polymer of formula (IV) is described in document EP2583988. Those skilled in the art will know how to adjust the preparation method described in the said document in the case of using different types of polyols.

[0021] According to an embodiment of the present invention, the filler is selected from at least one of mineral fillers and organic fillers, the mineral filler is selected from at least one of clay, quartz, calcium carbonate or chalk, hollow glass microspheres; the organic filler is selected from polyvinyl chloride (PVC), polyolefins, rubbers, ethylene vinyl acetate (EVA) or aromatic polyamide fibers.

[0022] According to a preferred embodiment of the present invention, R1 is a straight-chain or branched-chain alkyl group of C 12～16 of.

[0023] According to a preferred embodiment of the present invention, R2 is phenyl or naphthyl.

[0024] According to an embodiment of the present invention, the adhesive composition may further comprise a crosslinking catalyst (D), and based on the total weight of the composition, the content of the crosslinking catalyst (D) is 0.01-1%, preferably 0.01-0.5%, more preferably 0.01-0.2%.

[0025] Preferably, the crosslinking catalyst (D) is selected from at least one of titanium acetylacetonate and dibutyltin dilaurate (DBTL).

[0026] According to an embodiment of the present invention, the adhesive composition may further comprise a plasticizer, and based on the total weight of the composition, the content of the plasticizer is 0-30%, preferably 1-30%, more preferably 15-25%.

[0027] Preferably, the plasticizer is selected from at least one of diisodecyl phthalate (DIDP), diisononyl 1,2-cyclohexanedicarboxylate, and pentaerythritol tetrapentanoate.

[0028] According to an embodiment of the present invention, the adhesive composition may further comprise a adhesion promoter, and based on the total weight of the composition, the content of the adhesion promoter is 0-30%, preferably 1-30%, more preferably 5-15%.

[0029] Preferably, the adhesion promoter is selected from 3-aminopropyltrimethoxysilane (also known as AMMO).

[0030] According to an embodiment of the present invention, the adhesive composition may further comprise a moisture absorbent, and based on the total weight of the composition, the content of the moisture absorbent is 0-30%, preferably 1-30%, more preferably 1-5%.

[0031] Preferably, the moisture absorbent is selected from at least one of vinyltrimethoxysilane (VTMO), vinyltriethoxysilane (VTEO), or alkoxyarylsilane.

[0032] According to an embodiment of the present invention, the adhesive composition may further comprise a rheology modifier, and based on the total weight of the composition, the content of the rheology modifier is 0-30%, preferably 1-30%, more preferably 1-10%.

[0033] Preferably, the rheology modifier is selected from at least one of N,N'-ethane-1,2-diylbis(hexanamide), 12-hydroxy-N-[2-[(1-oxohexyl)amino]ethyl]octadecanamide, and N,N'-ethane-1,2-diylbis(12-hydroxyoctadecanamide). More preferably, the rheology modifier is selected from MAX, which is composed of N,N'-ethane-1,2-diylbis(hexanamide), 12-hydroxy-N-[2-[(1-oxohexyl)amino]ethyl]octadecanamide, and N,N'-ethane-1,2-diylbis(12-hydroxyoctadecanamide).

[0034] According to an embodiment of the present invention, the adhesive composition may further comprise a pigment, and based on the total weight of the composition, the content of the pigment is 0-20%, preferably 1-15%, and more preferably 1-5%. Preferably, the pigment is, for example, titanium dioxide.

[0035] According to an embodiment of the present invention, the adhesive composition may further comprise a UV stabilizer, and based on the total weight of the composition, the content of the UV stabilizer is 0-15%, preferably 0.1-8%, and more preferably 0.1-2%.

[0036] Preferably, the UV stabilizer is selected from benzotriazole, benzophenone, Tinuvin TM 770 or Tinuvin TM 765. Tinuvin TM 765 is a UV stabilizer composition composed of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 1-(methyl)-8-(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (CAS numbers: 41556-26-7 and 82919-37-7).

[0037] According to an embodiment of the present invention, the adhesive composition may further comprise a solvent, and based on the total weight of the composition, the content of the solvent is 0-20%, preferably 1-20%, and more preferably 1-10%. The solvent is selected from ethanol, isopropanol, etc.

[0038] In the present invention, unless otherwise specified, the sum of the weight percentages of the components in the composition is 100% by weight.

[0039] According to an embodiment of the present invention, the preparation method of the adhesive composition is:

[0040] Mix the raw materials to obtain the adhesive composition.

[0041] According to an embodiment of the present invention, the preparation method of the antioxidant is:

[0042] The compound shown in formula A undergoes a substitution reaction with the aromatic amine R2-NH2 to prepare the antioxidant;

[0043]

[0044] Wherein, R1 and R2 have the above meanings.

[0045] According to an embodiment of the present invention, the molar ratio of the compound shown in formula A to the aromatic amine is 1:1 to 3.

[0046] According to an embodiment of the present invention, in the preparation of the antioxidant, the reaction temperature is 60-120 °C and the reaction time is 12-24 h.

[0047] According to an embodiment of the present invention, in the preparation of the antioxidant, the substitution reaction is carried out under the action of an acid-binding agent and a catalyst. The acid-binding agent is potassium tert-butoxide, and the catalyst is Pd2(dba)3 and BINAP. The molar ratio of the acid-binding agent to the compound shown by formula A is 1:3-10.

[0048] According to an embodiment of the present invention, in the preparation of the antioxidant, the molar ratio of Pd2(dba)3 to the compound shown by formula A is 1:3-8; the molar ratio of BINAP to the compound shown by formula A is 1:3-8.

[0049] According to an embodiment of the present invention, in the preparation of the antioxidant, the substitution reaction is carried out under nitrogen protection.

[0050] According to an embodiment of the present invention, in the preparation of the antioxidant, the solvent for the substitution reaction is toluene. The amount of toluene used is 6-12 times the total mass of the reaction raw materials. After the reaction is completed, the antioxidant is obtained through vacuum distillation and column chromatography.

[0051] The present invention also provides the use of the above adhesive composition for bonding and sealing in the fields of building construction, motor vehicles, railways or aerospace industries, and shipbuilding.

[0052] Advantages of the present invention:

[0053] The present invention discloses an adhesive. The mechanical properties of the sample made from the cross-linked adhesive of the present invention are good. Even when soaked in boiling water or under high temperature and high humidity or low temperature conditions, it still has excellent mechanical properties. Specific embodiments

[0054] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to illustrate and explain the present invention exemplarily, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0055] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0056] The raw materials used in the examples are as follows:

[0057] Filler: C16T (a filler composed of natural calcium carbonate, obtained from LA PROVENCALE).

[0058] Crosslinking catalyst: Dibutyltin dilaurate (DBTL)

[0059] Plasticizer: Diisodecyl phthalate (DIDP)

[0060] Adhesion promoter: AMMO, an adhesion promoter obtained from EVONIK.

[0061] Humectant: VTMO, consisting of vinyltrimethoxysilane, obtained from EVONIK.

[0062] Rheology modifier: MAX, which consists of N,N'-ethane-1,2-diylbis(hexanamide), 12-hydroxy-N-[2-[(1-oxohexyl)amino]ethyl]octadecanamide, and N,N'-ethane-1,2-diylbis(12-hydroxyoctadecanamide), obtained from Elementis.

[0063] White pigment: Titanium dioxide, obtained from KRONOS INTERNATIONAL.

[0064] UV stabilizer: Tinuvin TM 765, obtained from BASF.

[0065] Solvent: Ethanol.

[0066] Example 1

[0067] Preparation of an adhesive:

[0068] (1) Preparation of silylated polymer (A0):

[0069] Introduce into a reactor 2200 (a polyether polyol with IOH of 9 to 11 mg KOH / g and a number average molecular weight of about 12,000, sold by COVESTRO), then add a dehydrating agent (p-toluenesulfonyl isocyanate, sold by COVESTRO), and heat the medium to 60 - 65 °C. Next, introduce IPDI, mix the mixture for 10 minutes, and then introduce catalyst KKATXK-664 (zinc carboxylate sold by King Industry). Then heat the mixture to 70 °C with stirring and hold for one hour. Then check the NCO index; if the theoretical NCO index is not reached, extend the reaction time by 15 minutes as needed.

[0070] When the theoretical NCO index is reached, add 1189 (n-butyl-3-aminopropyltrimethoxysilane from Evonik), and the mixture was stirred for 10 minutes. Then the reactor was placed in the cooling mode and VTMO and DINP (diisononyl phthalate) were added; then the mixture was kept stirring for 20 minutes.

[0071] A product consisting essentially of 85.53% weight / weight of the silylated polymer (A0) and 13.90% weight / weight of the DINP plasticizer was obtained.

[0072] (2) Preparation of the antioxidant:

[0073] 0.325 g (1 mmol) of the compound shown in formula A (R1 is dodecyl) and 0.093 g (1 mmol) of aniline were dissolved in 100 mL of toluene, then 0.0281 g (0.25 mmol) of potassium tert-butoxide, 0.229 g (0.25 mmol) of (Pd2(dba)3), and 0.156 g (0.25 mmol) of BINAP were added. The reaction was carried out at a constant temperature of 80 °C for 12 h under N2 until the reaction was completed. Toluene was removed by distillation under reduced pressure to obtain a crude product, and the obtained crude product was purified by silica gel column chromatography (the volume ratio of the eluent petroleum ether:ethyl acetate was 10:1) to obtain the antioxidant.

[0074] (3) The composition of the adhesive composition is as follows:

[0075] 30 wt% of the silylated polymer (A0), 30 wt% of the filler, 0.15 wt% of the antioxidant, 0.05 wt% of the crosslinking catalyst, 20 wt% of the plasticizer, 8.7 wt% of the adhesion promoter, 2 wt% of the moisture absorbent, 5 wt% of the rheology modifier, 2 wt% of the pigment, 0.1 wt% of the UV stabilizer, and 2 wt% of the solvent ethanol.

[0076] Example 2

[0077] The difference between Example 2 and Example 1 is that:

[0078] The composition of the adhesive composition is as follows:

[0079] 35 wt% of the silylated polymer (A0), 27 wt% of the filler, 0.17 wt% of the antioxidant, 0.05 wt% of the crosslinking catalyst, 18 wt% of the plasticizer, 8.68 wt% of the adhesion promoter, 2 wt% of the moisture absorbent, 5 wt% of the rheology modifier, 2 wt% of the pigment, 0.1 wt% of the UV stabilizer, and 2 wt% of the solvent ethanol.

[0080] Example 3

[0081] The difference between Example 3 and Example 1 is that:

[0082] The composition of the adhesive composition is as follows:

[0083] 28 wt% of a silylated polymer (A0), 32 wt% of a filler, 0.15 wt% of an antioxidant, 0.04 wt% of a crosslinking catalyst, 21 wt% of a plasticizer, 7.8 wt% of a bonding promoter, 2.5 wt% of a moisture absorbent, 4.41 wt% of a rheology modifier, 2 wt% of a pigment, 0.1 wt% of a UV stabilizer, and 2 wt% of a solvent ethanol.

[0084] Test Examples

[0085] 1.1 Use two identical stainless-steel plates of the following dimensions for the substrate: 100 mm × 25 mm × 2 mm. After cleaning the two plates with isopropyl alcohol, a rectangular gluing area with dimensions of 12.5 mm × 25 mm is defined at the end of each plate using tape.

[0086] On the gluing area of the first substrate plate, apply the adhesive composition prepared above in an amount equivalent to a 2-mm thickness. Next, stack the gluing area of the second substrate plate on the area thus coated to obtain an assembly, where the free ends of the two substrate plates are aligned on both sides of the two areas joined by the adhesive.

[0087] Keep the obtained assembly samples in a controlled-atmosphere room at 23 °C and 50% relative humidity for 14 days using clips for the crosslinking of the adhesive.

[0088] 1.2 Measure the shear strength immediately after crosslinking:

[0089] For each substrate tested, prepare 3 assembly samples according to point 1.1.

[0090] The two free ends of each sample are pulled by a tensile testing machine at a constant speed equal to 50 mm / min until the assembly breaks, and the stress applied is recorded, i.e., the initial break.

[0091] 1.3 Measure the shear strength after a period of time in boiling water:

[0092] For each substrate tested, prepare 3 assembly samples according to point 1.1.

[0093] Then immerse the said samples in boiling water for 6 hours, and then measure the breaking stress as shown in point 1.2.

[0094] 1.4 Measure the shear strength after temperature / humidity cycling:

[0095] For each substrate tested, prepare 3 assembly samples according to point 1.1.

[0096] Then subject the sample to an alternating cycle of 1 hour at 80 °C and 90% relative humidity and 1 hour at -20 °C, and repeat the cycle 24 times. Then measure the breaking stress as shown in point 1.2.

[0097] The test results are shown in Table 1 below.

[0098] Table 1

[0099]

[0100] Above, the embodiments of the present invention have been described by way of example. However, the protection scope of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An adhesive composition, characterized in that, Based on its total weight, it contains: 20 - 50 wt% of silylated polymer (A); 25 - 50 wt% of filler (B); and 0.05 - 10 wt% of antioxidant (C) represented by the following formula I; In Formula I, R1 is selected from straight-chain or branched-chain alkyl groups of C 12～20 ; R2 is selected from aryl.

2. The adhesive composition according to claim 1, wherein The silylated polymer (A) is selected from at least one of the compounds represented by the following formula II, formula III or formula IV: Among them, in Formula II, Formula III or Formula IV, R 3 are the same or different and each independently selected from C 1-6 alkylene; R 4 、R 5 are the same or different and are each independently selected from C 1-4 alkyl; X represents a divalent group selected from -NH- or -S-; f is an integer from 1 to 6; R 1 selected from C 1-6 alkylene group.

3. The adhesive composition according to claim 1, characterized in that, In formula I, R1 is a straight-chain or branched-chain alkyl group of C 12～16 ; Preferably, R2 is phenyl or naphthyl.

4. The adhesive composition according to claim 1, characterized in that, The adhesive composition further contains a crosslinking catalyst (D), and based on the total weight of the composition, the content of the crosslinking catalyst (D) is 0.01 - 1%; Preferably, the crosslinking catalyst (D) is selected from at least one of titanium acetylacetonate and dibutyltin dilaurate. Preferably, the adhesive composition further contains a plasticizer, and based on the total weight of the composition, the content of the plasticizer is 0 - 30%; Preferably, the plasticizer is selected from at least one of diisodecyl phthalate, diisononyl 1,2 - cyclohexanedicarboxylate, and pentaerythritol tetravalerate.

5. The adhesive composition according to claim 1, characterized in that, The adhesive composition further contains a adhesion promoter, and based on the total weight of the composition, the content of the adhesion promoter is 0 - 30%; the adhesion promoter is selected from 3 - aminopropyltrimethoxysilane. Preferably, the adhesive composition further contains a moisture absorbent, and based on the total weight of the composition, the content of the moisture absorbent is 0 - 30%; Preferably, the moisture absorbent is selected from vinyltrimethoxysilane, vinyltriethoxysilane or alkoxyarylsilane. Preferably, the adhesive composition further contains a rheology modifier, and based on the total weight of the composition, the content of the rheology modifier is 0 - 30%; The rheology modifier is selected from at least one of N,N'-ethane - 1,2 - diylbis(hexanamide), 12 - hydroxy - N - [2 - [(1 - oxohexyl)amino]ethyl]octadecanamide and N,N'-ethane - 1,2 - diylbis(12 - hydroxystearamide).

6. The adhesive composition according to claim 1, characterized in that, The adhesive composition further contains a pigment, and based on the total weight of the composition, the content of the pigment is 0 - 20%; preferably, the pigment is titanium dioxide. Preferably, the adhesive composition further contains a UV stabilizer, and based on the total weight of the composition, the content of the UV stabilizer is 0 - 15%. Preferably, the UV stabilizer is selected from benzotriazole, benzophenone, Tinuvin TM 770 or Tinuvin TM 765. Preferably, the adhesive composition further contains a solvent, and based on the total weight of the composition, the content of the solvent is 0 - 20%. Preferably, the solvent is selected from ethanol or isopropanol.

7. A method for preparing the adhesive composition according to any one of claims 1-6, characterized in that, The method is: Mix each raw material to obtain the adhesive composition.

8. The method according to claim 7, characterized in that, The preparation method of the antioxidant is: The compound shown in formula A undergoes a substitution reaction with arylamine R2 - NH2 to prepare the antioxidant; In formula A, R1 and R2 have the definitions as claimed; Preferably, the molar ratio of the compound shown in formula A to the arylamine is 1:1 to 3; Preferably, in the preparation of the antioxidant, the reaction temperature is 60 - 120 °C and the reaction time is 12 - 24 h.

9. The method according to claim 8, characterized in that, In the preparation of the antioxidant, the substitution reaction is carried out under the action of an acid-binding agent and a catalyst. The acid-binding agent is potassium tert-butoxide, and the catalyst is Pd2(dba)3 and BINAP. The molar ratio of the acid-binding agent to the compound shown by formula A is 1:3 to 10; Preferably, in the preparation of the antioxidant, the molar ratio of Pd2(dba)3 to the compound shown by formula A is 1:3 to 8; the molar ratio of BINAP to the compound shown by formula A is 1:3 to 8. Preferably, in the preparation of the antioxidant, the solvent for the substitution reaction is toluene, and the amount of toluene used is 6 to 12 times the total mass of the reaction raw materials. After the reaction is completed, the antioxidant is obtained by vacuum distillation and column chromatography.

10. Use of the adhesive composition according to any one of claims 1-6 for adhesion and sealing in the fields of building construction, motor vehicles, railway or aerospace industries, and shipbuilding.

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